The Present Application relates to an optical connector.
Hitherto, in an electronic device or apparatus such as a personal computer, a cellular phone, a PDA (personal digital assistant), a digital camera, a video camera, a music player, a game machine, or a car navigation device, in order to realize both a decrease in an overall size a casing thereof and an increase in the size of a display screen thereof, the casing is configured to be collapsible. In such a case, a flexible printed circuit (FPC) and conductive wires such as a fine coaxial cable are arranged so as to pass through an inside of a hinge portion that allows one casing to be pivotably connected with the other casing so that signals can be transmitted through parallel transmission.
Although a signal transmission speed is requested to increase in response to an increase in image resolution, since there is a limit in increasing the inside dimension of the hinge portion, it is practically impossible to arrange a conductive wire having a large width or diameter thereof. In addition, when a countermeasure against electro magnetic interference (EMI) is taken, the conductive wire will become larger in the width or diameter thereof.
In this regard, a method of optical transmission has been alternatively studied which is capable of transmitting a large amount of signals through serial transmission and is an excellent EMI countermeasure. An example is described in Japanese Patent Application No. 11-84174.
FIG. 13 is an perspective view of a conventional optical connector. As shown in the drawing figure of FIG. 13, an optical element portion, generally designated by reference numeral 870, is configured to receive therein an optical module including a light emitting element, a light receiving element and the like, and is coupled to a connector housing 811 by means of a coupling member 841. The connector housing 811 is provided with a groove-shaped guide portion 814 configured to allow a non-illustrated plug connected to a front end of a non-illustrated optical fiber to be inserted therein and an engagement wall portion 818 configured to be engaged with a front end of the plug. In addition, a pair of guide projections 831 is formed on a wall surface of the engagement wall portion 818, and the guide projections 831 are engaged with a pair of engagement holes formed in the plug, so that the plug is placed in position after insertion thereof.
The optical connector is provided with a clamping member 821 which is rotatably attached to the connector housing 811. A front end of the clamping member 821 is rotatably mounted on a rotation shaft 813 configured to project from a side surface of the engagement wall portion 818. The clamping member 821 is provided with elongated plate-like arm parts 822 configured to extend rearward from the front end of the clamping member 821. Moreover, latching portions 827 are connected to rear ends of the arm parts 822 so as to be engaged with the rear end of the plug, and an operation portion 825 allowing an operator to operate is connected to the rear ends of the latching portions 827.
When the plug is connected to the optical connector, the clamping member 821 is rotated from an attitude shown in the drawing figure of FIG. 13 to raise the operation portion 825, so that an upper surface of the guide portion 814 is open. Subsequently, the plug is inserted into the guide portion 814 from a rear side thereof, so that a front end surface of the plug comes into tight contact with the wall surface of engagement wall portion 818. In this case, the positioning of the plug is carried out by tightly fitting the guide projections 831 to be engaged with the engagement holes of the plug. Finally, when the clamping member 821 is rotated to lower the operation portion 825, the optical connector returns to assume the attitude shown in the drawing figure of FIG. 13. Owing to this configuration, the latching portions 827 are engaged with the rear end of the plug, and the plug is locked in a state of being connected to the optical connector.
However, according to the conventional optical connector, since the positioning of the plug is carried out by tightly fitting the guide projections 831 to be engaged with the engagement holes of the plug, it may be difficult for an operator to perform a connecting operation. Usually, when a plug connected to an optical fiber is connected to an optical connector, the guide projections 831 and the engagement holes are designed to have an extremely small dimensional tolerance since the positioning of a plug-side optical path relative to an optical connector-side optical path requires an extremely high degree of precision. For this reason, an operation of an operator moving the plug to cause the guide projections 831 to be inserted into the engagement holes requires a high degree of accuracy and is thus difficult to perform.
Furthermore, since various errors, such as, for example dimensional errors of the guide projections 831 per se, errors in attachment of the guide projections 831 to the engagement wall portion 818, and dimensional errors of the engagement holes of the plug are accumulated, it is difficult to secure highly precise adjustments between a plug-side optical path and a optical connector-side optical path.
Furthermore, as described above, since the positioning of the plug-side optical path and the optical connector-side optical path requires an extremely high degree of precision, not only the dimensional tolerance of the guide projections 831 and the engagement holes, but also all the dimensional tolerances of the respective members including the connection surface of the engagement wall portion 818 and the connection surface of the plug need to be set extremely low. Thus, it is necessary to perform the processing and assembly with high precision, and therefore the manufacturing time and the manufacturing cost must be increased.